Inside linebacker is a position they look at generally being worthy of a fourth-round pick and no higher. Whether you agree with that philosophy or not isn't the issue, it's still the way the current occupants of 1265 Lombardi operate. Other teams operate differently with varying degrees of success.
They took a Pro Bowl edge rusher and made him a mediocre (or worse) ILB, and persisted with that move after Matthews' shortcomings at the position were evident.
Before that they gave Brad Jones a surprisingly generous contract in 2013.
Before that they gave Hawk a generous contract after 2010.
Going back further, they took a top 5 pick in Hawk and converted him from OLB to ILB with the conversion to 3-4 rather than trade him.
There's a lot of evidence that Capers does not undervalue the position. It's a matter of valuing experience in the system at the ILB position over potential that can be acquired in the draft, and a willingness to pay for that in vet contracts has been evident. It goes to defensive complexity and confidence that a guy will know his role and perform within the scheme.
This is an explanation, not a defense. My preferred first round choice in 2015 was Kendricks; in the 2016 draft my preference was Ragland assuming the enlarged aorta was not an issue, which it was not evidently.